31 Oct 2016

More evidence for ‘planet-nine’ Unveiled

Planet-Nine-in-Outer-Space-artistic-depiction

The case for Planet Nine is growing. Two new findings presented at a planetary science meeting in Pasadena, Calif., have uncovered hints for the existence of this distant, mysterious world in the motions of known solar system objects.

The results could help astronomers home in on their target, which — if it really is out there — could fundamentally alter our understanding of the solar system.

The hunt for Planet Nine began in earnest in 2014 after astronomers Scott Sheppard and Chadwick Trujillo found 2012 VP113, a planetoid nicknamed "Biden." Its closest point to the sun in its orbit is 80 astronomical units — that is, 80 times the Earth-Sun distance of 93 million miles.

Objects like 2012 VP113 exist far beyond the typical denizens of the Kuiper belt, the icy ring of debris that stretches from Neptune's orbit at 30 AU out to 50 AU (and whose largest member is distant Pluto, sitting around 49 AU).

The scientists also noticed that 2012 VP113 and another far-out mini-world named Sedna were making their closest approaches to the sun at similar angles — which could mean that something massive but unseen was tugging on both their orbits. Since the scientists could not directly see a planet in the darkness of our solar system, they would have to keep searching for its gravitational fingerprint on the motions of other bodies.

Then, early this year, California Institute of Technology scientists Konstantin Batygin and Mike Brown found that the paths of half a dozen extremely distant objects seemed to be similarly tilted relative to the plane of the solar system, and that their perihelia — their closest points to the sun — seemed to cluster together. They estimated that a Planet Nine would weigh about 10 Earth masses and take somewhere from 10,000 to 20,000 years to orbit the sun.

Now, a team led by Renu Malhotra, a planetary scientist at the University of Arizona, has examined the orbits of four extreme Kuiper belt objects with the longest-known orbital periods and found an elegant relationship among their orbits: They can be described essentially in simple, whole-number ratios. This suggests that they're pulled into these resonances by the gravity from an unseen massive object.

Malhotra was taken aback after discovering the small integer ratios. "It was like, 'Wow, why hasn't somebody else noticed this before?'" she recalled.

Malhotra's team calculated that such a planetoid would be 10 times the mass of Earth and would orbit the sun roughly every 17,000 years — which fits with the Caltech scientists' range estimate of 10,000 to 20,000 years. At its farthest point, this planet would lie a whopping 665 astronomical units from the sun. The results were published in the Astrophysical Journal Letters.

Meanwhile, Brown and Batygin have found more potential evidence of Planet Nine's influence. Their calculations, accepted for publication in the Astrophysical Journal, suggest that the solar system's slight tilt relative to the sun might have been caused by the massive world's pull.

Since the mid-1800s, scientists have wondered why the plane of the solar system — the plane in which all the planets orbit — is tilted 6 degrees relative to the spin axis of the sun, said lead author Elizabeth Bailey, an astronomer and Ph.D. student at Caltech. Given that Planet Nine is suspected to be circling the sun at an even more extreme angle, the scientists calculated that it could indeed have pulled the planets out of alignment with the sun, causing the 6-degree mismatch.

"From our vantage point, it looks like it's the sun that's tilted; but really it's the plane of the planets precessing around the total angular momentum of the solar system, just like a top," she said.

Neither study is a slam-dunk case for the planet's existence, scientists said, but the evidence continues to mount.

The results from both teams were presented at the joint 48th meeting of the Division for Planetary Sciences of the American Astronomical Society and 11th European Planetary Science Congress in Pasadena.

30 Oct 2016

NASA's New 'Intruder Alert' System Spots An Incoming Asteroid

A telescope in Hawaii first spotted an errant rock headed toward Earth. The Scout program quickly flagged it for follow-up observations. Rob Ratkowski/Courtesy of Pan-STARRS

telescope-1_custom-d0ecf5dc554998f98616d5f349d37ab2f8ec2ec0-s800-c85

A large space rock is going to come fairly close to Earth later tonight. Fortunately, it's not going to hit Earth, something astronomers are sure of thanks in part to a new tool NASA is developing for detecting potentially dangerous asteroids.

The tool is a computer program called Scout, and it's being tested at NASA Jet Propulsion Laboratory in Pasadena, Calif. Think of Scout as a celestial intruder alert system. It's constantly scanning data from telescopes to see if there are any reports of so-called Near Earth Objects. If it finds one, it makes a quick calculation of whether Earth is at risk, and instructs other telescopes to make follow-up observations to see if any risk is real.

NASA pays for several telescopes around the planet to scan the skies on a nightly basis, looking for these objects. "The NASA surveys are finding something like at least five asteroids every night," says astronomer Paul Chodas of JPL.

But then the trick is to figure out which new objects might hit Earth.

"When a telescope first finds a moving object, all you know is it's just a dot, moving on the sky," says Chodas. "You have no information about how far away it is. "The more telescopes you get pointed at an object, the more data you get, and the more you're sure you are how big it is and which way it's headed. But sometimes you don't have a lot of time to make those observations.

"Objects can come close to the Earth shortly after discovery, sometimes one day, two days, even hours in some cases," says JPL's Davide Farnocchia. "The main goal of Scout is to speed up the confirmation process."

The rock whizzing past Earth tonight was discovered on the night of Oct. 25-26 by the NASA-funded Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) on Maui, Hawaii. Within a few hours, preliminary details about the object appeared on a web page maintained by the Minor Planet Center at the Smithsonian Astrophysical Observatory. Scout did a quick analysis of the preliminary details and determined that the object was headed for Earth, but would miss us by about 310,000 miles.

Additional observations by three telescopes, one operated by the Steward Observatory, another called Spacewatch, and a third at the Tenagra Observatories, confirmed the object would miss Earth by a comfortable margin. Astronomers were also able to estimate the size of the object: somewhere between 5 meters and 25 meters across. In case you're interested, full details about the object's trajectory can be found here.

Scout is still in the testing phase. It should become fully operational later this year.

Now Scout is mainly dealing with smallish, very nearby objects. Complementing Scout is another system which is already operational called Sentry.
  
Sentry's job is to identify objects large enough to wipe out a major city that might hit Earth in the next hundred years. "Our goal right now is to find 90 percent of the 140 meter asteroids and larger," says Chodas, but right now he estimates they're only able to find 25-30 percent of the estimated population of objects that size.

That number should get better when a new telescope being built in Chile called the Large Synoptic Survey Telescope comes on line. NASA is also considering a space telescope devoted to searching for asteroids.

OK, so let's say you find one of these monster rocks heading for Earth. What then? Astronomer Ed Lu says there is something you can do. He's CEO of an organization called B612. It's devoted to dealing with asteroid threats.

"If you know well in advance, and by well in advance I mean 10 years, 20 years, 30 years in advance which is something we can do, " says Lu, "then you can divert such an asteroid by just giving it a tiny nudge when it's many billions of miles from hitting the Earth."

NASA and the European Space Agency are developing a mission to practice doing just that.

Lu says in the last decade people who should worry about such things have begun to make concrete plans for dealing with dangerous asteroids.

"I believe in the next 10 to 15 years we'll actually be at the point where we as humans can say, 'Hey, we're safe from this danger of large asteroids hitting the Earth,' " he says.

In the meantime, we'll just have to hope that luck is on our side.

By Joe Palca Correspondent, Science Desk

 

29 Oct 2016

Astrophoto Alert: Strange swirling hexagonal structure on Saturn spotted

Ashampoo_Snap_2016.10.29_00h02m30s_003_

The Cassini probe, investigating Saturn, has detected a strange swirling structure, hexagonal in shape, at the north pole of the planet. The structure appears to regularly change colour.

Saturn is the sixth planet from the Sun and the second-largest in the solar system, after Jupiter. Saturn is a gas giant and its radius is some nine times that of Earth. The most striking feature of Saturn is its nine continuous main rings and three discontinuous arcs. However, it is a different, somewhat mysterious feature that has attracted recent interest from astrophysicists.

Cassini’s investigations into the Saturnian region (Saturn and its moons) have focused in on a 20,000-mile hexagonal-shaped formation. The regular changing of colours is possible linked to changing the seasons (with colours alternating between blues and yellows.) Four Earth years are sufficient to see some colour change, although the full cycle could take the time period to move through all of the Saturn’s seasons, which are equal to 29 Earth years. The region of interest is possibly of a similar nature to Jupiter’s famous red spot.
 
NASA scientists think the colour change is connected to the production of photochemical hazes in the atmosphere, coinciding with the Saturnian summer solstice (that is, the influence of shifting patterns of solar heating.) Here it is reasoned that as sunlight reaches the planet, the heat produced generates aerosols. Sufficed volume of gas then leads to a colour changes in the atmosphere within the region of the hexagon.

It is thought the hexagon is some form of six-sided jet stream that rotates at a similar velocity to the planet. The rate of air blasted upwards is thought to be over 200 miles per hour. The hexagon is made of a band of upper-atmospheric winds which creates its shape.

The cause of the structure could be some form of permanent weather feature, such as a hurricane like wind. The pattern of the wind is most probably influenced by solar activity. This means the sun generates the aerosols, affects their colour, and accounts for the atmospheric activity.

Aside from the range structure, Saturn’s cloud formation is also attracting interest. Saturn's clouds are shaped by a branch of physics called fluid dynamics. This describes the motion of gases and liquids.

28 Oct 2016

3D Print your own Universe

The most comprehensive models of the universe are simulated by supercomputers -- not the kind of digital files the travel quickly across the Internet.

A new model of the cosmic microwave background, the oldest light in the universe, is a bit more nimble. Researchers at Imperial College London designed and printed a CMB map using a 3D printer.

The files are available for anyone to download.

The cosmic microwave background formed when the universe was only 380,000 years old. The universe is estimated to be 13.8 billion years old.

CMB was the first radiation to travel freely through the universe in the wake of what cosmologists refer to as recombination. Roughly 380,000 years after the Big Bang, the hot, exploded plasma of the universe began to cool and protons and electrons combined to form neutral hydrogen.

Recombination allowed photons to travel longer distances, and thermal energy spread through the universe. The cosmos became transparent instead of opaque.

"Differences in the temperature of the CMB relate to different densities, and it is these that spawned the formation of structure in the universe -- including galaxies, galaxy clusters and superclusters," Dave Clements, a physicist at ICL, explained in a news release.

Scientists have developed many maps of the ancient propagating photons, but they're often confusing -- the data difficult to parse. Researchers are hopeful their latest model is more accessible.

"Presenting the CMB in a truly 3D form, that can be held in the hand and felt rather than viewed, has many potential benefits for teaching and outreach work, and is especially relevant for those with a visual disability," Clements said.

The modeling efforts of Clements and his colleagues is detailed in a new paper, published this week in the European Journal of Physics.

Kepler Catalogues ‘Heartbeat stars’

astronomers-characterize-largest-batch-of-heartbeat-stars

NASA's Kepler space telescope has recently discovered a number of interesting celestial bodies named as heartbeat stars. The rare astronomical objects spotted lately are commonly referred as binary stars.

The binary stars are two huge stars that orbit around each other. Certain binary stars are called heartbeat stars because if the brightness of the two stars is mapped over time they would resemble an electrocardiogram, a graph that portrays the activity of human heart.

Since the binary stars orbit each other in an elongated elliptical pathway they are more suitable for scientists to study the gravitational effects that exist between each other. As far as heartbeat stars are concerned, interestingly, the distance between the stars varies extensively from time to time as they orbit each other in elliptical paths.

The stars could get as close as few stellar radii to each other and sometimes 10 times farther from one another during the course of an orbit. When the stars get too close due to the gravitational pull exhibited by each other, they tend to become ellipsoidal in shape. The change in shape also affects their brightness; hence the resultant light effects vary from time to time.

This is similar to the "tidal force" that causes waves on Earth. The discovery of heartbeat stars is significant since they help scientists to get better understanding of tidal force and how it works on other astronomical objects as well.

It is also noted in the NASA's Jet Propulsion Laboratory report that the tidal forces causes the heartbeat stars to ring or vibrate when they are close to each other. This is caused as a result of fluctuations in the diameter of the stars due to gravitational pull while in close proximity.

"You can think about the stars as bells, and once every orbital revolution, when the stars reach their closest approach, it's as if they hit each other with a hammer," said Avi Shporer, the lead author of the study and NASA Sagan postdoctoral fellow at NASA's Jet Propulsion Laboratory, Pasadena, California, in press release.

Shporer noted that one or both the heartbeat stars vibrate as they revolve around the orbit; however, when they get close to each other they behave as if they are "ringing very loudly."

Kepler, which is currently on its K2 mission, has discovered several heartbeat stars in years. A star named KOI-54 that appears brighter every 41.8 days was spotted by Kepler and a report on KOI-54 was published in a study in 2011. Yet again in 2012 after Kepler discovered 17 new astronomical objects the term "heartbeat stars" came into existence.

The study on heartbeat stars is published in The Astrophysical Journal.

26 Oct 2016

European Countries to invest £5 billion a year on new rocket launchers

_79472813_a6udEU officials said today they planned to invest 12 billion euros by 2020 to develop new rockets to launch satellites for defence and data-driven businesses and reduce reliance on Russian launchers.

With limited options to launch orbiters and Russia controlling a large share of the market, businesses currently wait years for a window to put satellites in space.

The European Commission wants to help Europe's top rocket contractor, Airbus Safran Launchers, to develop the Ariane 6 rocket by 2020 to better compete with U.S. and Russian rivals on cost and payload size.

Existing Ariane launchers cost roughly 150 million euros compared to 80 million for Russia's Soyuz, EU officials said.
 
"We don't want to use the other launchers. We are now using the Soyuz because there is no other way," Europe's Industry Commissioner Elzbieta Bienkowska told reporters.

With the global space industry growing faster than any other sector, the EU unveiled its strategy on Wednesday to ensure it does not fall behind in sectors, including defence, that use earth-observation data.

"We know who are the biggest global space powers: It is the U.S., it is Russia and China and India are coming so we want to be second or third," Bienkowska said.
 
The Commission plans to promote the use of its own global satellite navigation system Galileo in mobile phones and make the data available for business.

Europe will launch more than 30 satellites over the next decade to complete Galileo, which will work in tandem with the U.S. GPS system, EU officials said.

"Galileo data will be much more precise than GPS," Bienkowska said.

Russia and China have launched their own global positioning systems to underpin their defence industries and civilian commerce.

Europe is the world's third largest satellite manufacturer and the 28-nation bloc hopes investment in the space sector can increase the number of related jobs from the current 230,000.

"The benefit for the economy from one euro invested in space is seven euros back," Bienkowska said. (Editing by Andrew Roche)

An array of Canon Cameras is helping astronomers discover new galaxies

dragonfly_48-12When Astronomer Pieter van Dokkum was looking for ways to study galaxies, he turned to the equipment he was familiar with as an amateur photographer. Thanks in part to some advanced optical coatings, he and his research team have been able to discover previously unseen galaxies.

In 2011, van Dokkum and fellow professor and astronomer Roberto Abraham, were discussing ways to find a way to get a better look into the very diffuse cosmic light that's scattered by traditional telescopes like Hubble. Van Dokkum's thoughts turned to his consumer imaging equipment, and some claims Canon was making about its then-recently-released 400mm F2.8L II.

Introduced in August the previous year, the 400mm F2.8L II offers what Canon calls 'a Subwavelength Structure Coating (SWC), which uses microscopic cone-shaped structures smaller than a wavelength of visible light' to reduce internal reflections and scattered light. This kind of coating would theoretically help collect enough light to study galaxies with low 'surface brightness', and sure enough, it did. Says van Dokkum: 'We compared their performance to those of the best reflecting telescopes, and found that they produce almost an order of magnitude better suppression of the wings of the point spread function - probably in part because of the SWC coatings.' In short, the 400mm F2.8L II fitted the bill.

dragonfly_48-4More lenses were acquired and the Dragonfly Telephoto Array was born (clustering lenses allows researchers to increase the effective aperture of the system). Van Dokkum and Abraham started with eight lenses, and now operate two mounts with a total of 48 lenses.

You won't find a Canon EOS 5DSR behind anywhere on the array, though. Each lens is attached to its own science-grade 8MP CCD camera, and has a custom astronomical filter slotted in. There's a custom-built connector between each camera and the lens that can drive focus, and an Intel Compute Stick attached to each camera takes care of data recording and some processing. It's all controlled by a central computer that can carry out commands like 'auto-observe Mars' and 'expose 900 seconds'.

The array has helped examine much-observed heavenly bodies like the Coma Cluster, where they've been able to identify what the research team has dubbed 'ultra diffuse galaxies.' They continue to discover more of these galaxies with the help of Dragonfly, and aim to keep learning about their variety and formation.

OpenStack Goes Inside Atoms, Across Galaxy

Dr. Rosie Bolton, University of Cambridge

6105BARCELONA  OpenStack Summit 2016

OpenStack is going from the infinitesimal to the infinite. Researchers are using the cloud platform to look inside atoms today, while the builders of an innovative telescope array hope to use the software to peer across the galaxy and back 400 million years in time.

The two projects are very different from each other. What they have in common is that they're generating prodigious amounts of data, and looking to OpenStack to manage it all.

CERN, the European Organization for Nuclear Research, is using OpenStack to manage data for several of its key experiments. These include the Large Hadron Collider, which at 27 kilometres around is "the largest machine on Earth," said Tim Bell, compute and monitoring group leader at CERN, during a keynote at OpenStack Summit Tuesday. The collider fires beams of photons at each other, measuring the results to determine the properties of subatomic particles. One key component for detecting collisions is a machine called the Compact Muon Solenoid. "It's a very strange term, given that it weighs 14,000 tonnes, to call it compact," Bell said.

CERN's computing infrastructure has to be able to handle 1 billion collisions per second. That demand is driving the need for OpenStack, Bell said.

And that's not the only experiment CERN is running. "I have the honour of having an antimatter factory just down the road from my office," Bell said. The apparatus assembles positrons, antiprotons and neutrons to make anti-hydrogen, which scientists experiment on to determine antimatter properties, such as whether antimatter rises in gravity.

20110822cmsAll that science drives the need for a lot of compute. CERN stores 160 petabytes of data on tape, including 0.5 PB per day between June and August of this year. The organization anticipates a 60x compute increase by 2023, but the budget outlook for servers and people is flat, Bell said.

OpenStack helps CERN keep up with demand. CERN is using OpenStack on more than 190,000 cores in production, with more than 90% of CERN compute resources virtualized, 5,000 virtual machines migrated from old hardware in 2016, and more than 100,000 cores to be added in the next six months.

After Bell described how OpenStack is exploring the infinitesimal, the University of Cambridge's Dr. Rosie Bolton talked about OpenStack in the infinite. Or near-infinite, at any rate.

Bolton is part of a consortium building the Square Kilometre Array, a vast radio telescope due to go online in 2023. One part of the SKA will be located in the Western Australian desert, with 130,000 individual antennas in 512 clusters, over an 80-kilometre spread. The other part of the SKA will be in the Karoo desert in South Africa, with 197 antennas over 150 kilometres. The antennas will send data to Science Data Processors about 500 kilometres away from their separate antennas -- Perth, Australia and Cape Town, South Africa -- which then distribute the information around the world.

The antennas will be used to pick up signals going 400 billion years back in time, to observe the formation of the first stars. Separately, the SKA will observe several dozen pulsar stars spread around the galaxy. Pulsars send out pulses of radio activity with extremely precise regularity; by observing changes in the radio activity, astronomers hope to be able to detect gravity waves that span the galaxy.

The compute needs for the SKA will be enormous. Computers will need to ingest 400 gigabytes per second, generate and destroy 1.3 zettabytes of data and then preserve and ship 1 petabyte per day of science data, Bolton said.

The SKA consortium will build the compute facility toward the end of the first phase of construction of the telescope arrays, which is due in 2023. Bolton said she hopes to pique the OpenStack community's interest now, so OpenStack becomes a suitable platform for that kind of science when the SKA is ready to build its compute centre. "It's a long way off, but if we start now we hope to get the OpenStack community interested," Bolton said.

As part of its criteria, the SKA is looking to make the compute facility futureproof. It plans to have the telescope arrays online for 50 years, and needs a platform that can mature over that time and not need to be completely replaced

25 Oct 2016

Latest dark matter searches leave scientists empty-handed

101816_EC_darkmatter_inlineIn initial searches, proponents of WIMPs expected that the particles would be easy to find. “It was thought to be like, ‘OK, we’ll run the detector for five minutes, discover dark matter, and we’re all done,’” says physicist Matthew Szydagis of the University at Albany in New York, a member of LUX. That has turned into decades of hard work. As WIMPs keep failing to turn up, some scientists are beginning to become less enamoured with the particles and are considering other possibilities more closely.

One alternative dark matter contender now attracting more attention is the axion. This particle was originally proposed decades ago as part of the solution to a particle physics quandary known as the strong CP problem — the question of why the strong nuclear force, which holds particles together inside the nucleus, treats matter and antimatter  equally. If dark matter consists of axions, the particle could therefore solve two problems at once.

Axions are small fry as dark matter goes — they can be as tiny as a millionth of a billionth the mass of a WIMP. The particles interact so feebly that they are extremely difficult to detect. If axions are dark matter, “you’re sitting in an enormous, dense sea of axions and you don’t even notice them,” says physicist Leslie Rosenberg of the University of Washington in Seattle, the leader of the Axion Dark Matter eXperiment. After a recent upgrade to the experiment, ADMX scientists are searching for dark matter axions using a magnetic field and special equipment to coax the particles to convert into photons, which can then be detected.

Although WIMPs and axions remain the front-runners, scientists are beginning to move beyond these two possibilities. In between the featherweight axions and hulking WIMPs lies a broad range of masses that hasn’t been well explored. Scientists’ favorite theories don’t predict dark matter particles with such intermediate masses, says theoretical physicist Kathryn Zurek of Lawrence Berkeley National Laboratory in California, but that doesn’t mean that dark matter couldn’t be found there. Zurek advocates a diverse search over a broad range of masses, instead of focusing on one particular theory. “Dark matter direct detection is not one-size-fits-all,” she says.

In two papers published in Physical Review Letters on January 7 and September 14,  Zurek and colleagues proposed using superconductors — materials that allow electricity to flow without resistance — and superfluid's, which allow fluids to flow without friction, to detect light dark matter particles. “We are trying to broaden as much as possible the tools to search for dark matter,” says Zurek. Likewise, scientists with the upcoming Super Cryogenic Dark Matter Search SNOLAB experiment, to be located in an underground lab in Sudbury, Canada, will use detectors made of germanium and silicon to search for dark matter with smaller masses than the xenon experiments can.

101816_EC_darkmatter_inline2Scientists have not given up on xenon WIMP experiments. Soon some of those experiments will be scaling up — going from hundreds of kilograms of liquid xenon to tons — to improve their chances of catching a dark matter particle on the fly. The next version of XENON100, the XENON1T experiment (pronounced “XENON one ton”) is nearly ready to begin taking data. LUX’s next generation experiment, known as LUX-ZEPLIN or LZ, is scheduled to begin in 2020. PandaX-II scientists are also planning a sequel. Physicists are still optimistic that these detectors will finally find the elusive particles. “Maybe we will have some opportunity to see something nobody has seen,” says Xiangdong Ji of Shanghai Jiao Tong University, the leader of PandaX-II. “That’s what’s so exciting.”

In the sea of no detections of dark matter, there is one glaring exception. For years, scientists with the DAMA/LIBRA experiment at Gran Sasso have claimed to see signs of dark matter, using crystals of sodium iodide. But other experiments have found no signs of DAMA’s dark matter. Many scientists believe that DAMA has been debunked. “I don't know what generates the weird signal that DAMA sees,” says Hooper. “That being said, I don't think it's likely that it’s dark matter.”

But other experiments have not used the same technology as DAMA, says theoretical astrophysicist Katherine Freese of the University of Michigan in Ann Arbor. “There is no alternative explanation that anybody can think of, so that is why it is actually still very interesting.” Three upcoming experiments should soon close the door on the mystery, by searching for dark matter using sodium iodide, as DAMA does: the ANAIS experiment in the Canfranc Underground Laboratory in Spain, the COSINE-100 experiment at YangYang Underground Laboratory in South Korea, and the SABRE experiment, planned for the Stawell Underground Physics Laboratory in Australia.

Scientists’ efforts could still end up being for naught; dark matter may not be directly detectable at all. “It’s possible that gravity is the only lens with which we can view dark matter,” says Szydagis. Dark matter could interact only via gravity, not via the weak force or any other force. Or it could live in its own “hidden sector” of particles that interact among themselves, but mostly shun normal matter.

Even if no particles are detected anytime soon, most scientists remain convinced that an unseen form of matter exists. No alternative theory can explain all of scientists’ cosmological observations. “The human being is not going to give up for a long, long time to try to search for dark matter, because it’s such a big problem for us,” says Ji

Powerful New Camera Will Observe How First Stars Formed

lmt-night_0

A group of astronomers at Arizona State University is seeking answers to such questions as part of an international experiment that has been awarded more than $6 million in funding from the National Science Foundation to help build a uniquely sensitive camera, called TolTEC, to probe these mysteries.

"Half the light from stars in the universe is absorbed by clouds of interstellar dust and then re-radiated at long wavelengths invisible to the human eye," said Philip Mauskopf, of Arizona State University's School of Earth and Space Exploration (SESE). "Astronomical observations at these wavelengths can let us see into the cores of stellar nurseries where new stars are forming."

Mauskopf, a professor in SESE, is the leader of the ASU team that will design and construct the optics for the new camera. The team will also develop the electronics for producing images from the instrument's superconducting detectors.

The new camera will be attached to a giant telescope in Mexico. On top of the 15,000-foot Sierra Negra in the state of Puebla sits the Large Millimeter Telescope (pictured above), with a 50-meter (164-foot) diameter main mirror.

It is the largest telescope in the world designed to operate at a wavelength of 1 millimeter, ideal for making detailed study of the dusty universe. The construction of this telescope, with contributions from the University of Massachusetts, has been the biggest scientific project in the history of Mexico.

Over the next three years, an international consortium, led by UMass, will build the golf-cart-size TolTEC cryogenic camera for the Large Millimeter Telescope. It will survey the universe, imaging radiation from dust at millimeter-wavelengths across large areas of sky.

The astronomers expect these images will reveal millions of previously unknown galaxies that are invisible to standard optical telescopes due to their large dust content.

Watch again my program ‘In Search of the First Stars”

"Over the last decade, smaller cameras and telescopes have discovered thousands of these galaxies," Mauskopf said. "This new project will allow a complete census of dusty galaxies in the universe and enable us to truly begin to understand their properties."

Because of interstellar dust, star-forming regions such as the Eagle Nebula (M16) show relatively little when observed in visible light. This infrared view by the Herschel Space Observatory shows star formation activity inside the giant cloud of dusty gas. But the new TolTEC camera (with ASU optics and electronics) will produce views of stellar nurseries like this with finer detail.

In addition to Mauskopf, the ASU team includes postdoctoral scholar Sean Bryan, electrical engineer Hamdi Mani, mechanical engineer Matt Underhill as well as graduate student and NASA Earth and Space Science fellow Sam Gordon and Barrett Honors College student Rhys Kelso.

"To get the best images, we have to supercool the optics and the superconducting detectors," Mauskopf said. "While developing this kind of superconducting technology can be difficult, the detectors and readout electronics we are using for TolTEC are very similar to ones we have already developed for use on balloon-borne telescopes at shorter wavelengths."

Once the TolTEC camera is completed, it will be mounted on the Large Millimeter Telescope and begin a two-year program of three large sky surveys covering hundreds of square degrees. These surveys will target regions where there are known dust clouds in our own galaxy. They will also target regions where there is relatively little local dust so that more distant objects are visible for comparison with deep optical images containing large numbers of galaxies.

Observations that require today’s telescopes five years to complete will be done in a little more than a week with TolTEC.

"It’s hard to grasp the increased capabilities of the new instrument," said Grant Wilson of UMass, principal investigator for TolTEC. "The combination of the new camera and the LMT requires a new outlook on what types of investigations are possible."

9557065177_0199fb6c28_h_0The details of the TolTEC surveys will be worked out in consultation with the international astronomical community through a series of workshops led by members of the TolTEC scientific advisory board. Data from the surveys will be made public as quickly as possible to allow the maximum scientific return.

The data from TolTEC will enable cosmologists, such as SESE's Evan Scannapieco, to trace the mysterious mechanism that is shutting off star formation in giant galaxies. It will also help astronomers including SESE's Judd Bowman, Rogier Windhorst, James Rhoads and Sangeeta Malhotra, who are using other methods to directly observe the oldest and most distant galaxies responsible for the re-ionization of the hydrogen gas in the early universe.

"Designing and building this camera will be a wonderful hands-on opportunity for SESE students and researchers," Mauskopf said. "And the end result will be a powerful new tool for studying the universe."

Other partners in TolTEC include the National Institute of Standards and Technology, Northwestern University, the University of Michigan, Cardiff University (UK), and the National Institute of Astrophysics, Optics and Electronics in Mexico.

Top photo: Researchers and students at the School of Earth and Space Exploration will design and build the optics and electronics for a new, highly sensitive camera, dubbed TolTEC, for the Large Millimeter Telescope in Mexico. The camera will enable astronomers to observe deep inside galactic clouds of obscuring dust in regions of space where stars are being born. It will also help cosmologists trace the evolution of galaxies in the early universe. Image by LMT/James Lowenthal

24 Oct 2016

The Night Sky: November 2016

Untitled-1

Northern hemisphere observers can once again use Orion, which rises in mid-evening though it is not at its very best until after midnight. Much of the Hunter's retinue is on view - Capella, Aldebaran, the Twins - though Sirius does not appear until later. Ursa Major is still low in the north, and Arcturus has disappeared; the W of Cassiopeia is almost at the zenith. We are losing the Summer Triang...le as a dominant feature, and Altair sets before midnight. Pegasus is still there, with Andromeda and Perseus; Cetus and Eridanus sprawl across the southern aspect, but we have to ail intents and purposes lost Fomalhaut in the evening twilight. This is a good time of the year to track the Milky Way, from Cygnus right across the zenith and down to Gemini in the east.

My new program: 'The Clouds of Magellan' will be available to watch soon :)

From southern countries, this is an ideal time to study the Clouds of Magellan, which, with the Southern Birds, are almost overhead. Orion is with us once more, and Sirius shines brilliantly in the east; Canopus is high up, and it is interesting to compare the two. Sirius looks much the brighter, and one has to use one's imagination to realize that compared with Canopus it is puny; according to the figures in the Cambridge catalogue, it would take more than 7500 stars of the luminosity of Sirius to equal the power of Canopus. Achernar is high, and the Cross still rather low in the south. The Square of Pegasus is setting in the north-east, but Andromeda remains visible low over the horizon. Cetus is well displayed, and we can see the whole of the River Eridanus, from the area of Orion through to the far south.

image1

234 stars from a sample of 2.5 million show odd pulsing signal which could indicate alien life

hs-1996-22-a-web_printA new study by astronomers from Laval University in Canada identified 234 stars out of a sample of 2.5 million which display odd pulsing signal. They believe the pulsing is similar to an intelligent alien race trying to make a contact.

Collective Evolution reports that Ermanno Borra and Eric Trottier from the university studied the samples from 2.5 million stars that were part of the Sloan Digital Sky Survey project. A previous study by Borra led them to conclude the signals recorded could be from aliens based on his envision of the shape of an extra-terrestrial intelligence (ETI) signal.

The project created the most detailed 3D maps of the universe with deep multi-colour images of one-third of the sky and spectra for over 3 million astronomical objects.

The two astronomers used a Fourier transform analysis and found on 234 stars signals in the F2 to K1 range. The signals could not be caused by instrumental or data analysis effects since it is present in only a very small fraction of stars within a narrow spectral range. Among the other possibilities that Borra and Trottier considered were rotational transitions in molecules, rapid pulsations, Fourier transform of spectral lines and signals generated by ETI.

But they acknowledge their finding is not the discovery needed to confirm humans are not alone in the universe. More work is needed to even suggest that theory.

The Breakthrough Listen Initiative, a scientific and technological explorations programme, with Stephen Hawking and Facebook CEO Mark Zuckerberg on its board, plans to expand on the study’s findings since more proof is needed from an outside source to prove the claims of the astronomers are true.

The initiative adds, “Internationally agreed-upon protocols for searches for evidence of advanced life beyond Earth (SETI) require candidates to be confirmed by independent groups using their own telescopes, and for all natural explanations to be exhausted before invoking extra-terrestrial agents as an explanation.”

23 Oct 2016

The universe is expanding at an accelerating rate – or is it?

053141_25-141159_0

As a new bright nova was today discovered in the constellation of Lepus (The Hare): Mag 16:  RA 05h 31m 41.25s DEC -14d 11m 59.0s., [ Shown above ] Nova have become the new tool to help work out if our Universe is expanding --- Maybe it isn’t, and there is NO Dark Matter either!

By Stuart Gillespie

Five years ago, the Nobel Prize in Physics was awarded to three astronomers for their discovery, in the late 1990s, that the universe is expanding at an accelerating pace.

Their conclusions were based on analysis of Type Ia supernovae – the spectacular thermonuclear explosions of dying stars – picked up by the Hubble space telescope and large ground-based telescopes. It led to the widespread acceptance of the idea that the universe is dominated by a mysterious substance named 'dark energy' that drives this accelerating expansion.

Now, a team of scientists led by Professor Subir Sarkar of Oxford University's Department of Physics has cast doubt on this standard cosmological concept. Making use of a vastly increased data set – a catalogue of 740 Type Ia supernovae, more than ten times the original sample size – the researchers have found that the evidence for acceleration may be flimsier than previously thought, with the data being consistent with a constant rate of expansion.

The study is published in the Nature journal Scientific Reports.

Professor Sarkar, who also holds a position at the Niels Bohr Institute in Copenhagen, said: 'The discovery of the accelerating expansion of the universe won the Nobel Prize, the Gruber Cosmology Prize, and the Breakthrough Prize in Fundamental Physics. It led to the widespread acceptance of the idea that the universe is dominated by "dark energy" that behaves like a cosmological constant – this is now the "standard model" of cosmology.

'However, there now exists a much bigger database of supernovae on which to perform rigorous and detailed statistical analyses. We analysed the latest catalogue of 740 Type Ia supernovae – over ten times bigger than the original samples on which the discovery claim was based – and found that the evidence for accelerated expansion is, at most, what physicists call "3 sigma". This is far short of the 5 sigma standard required to claim a discovery of fundamental significance.

Q-Continuum

'An analogous example in this context would be the recent suggestion for a new particle weighing 750 GeV based on data from the Large Hadron Collider at CERN. It initially had even higher significance – 3.9 and 3.4 sigma in December last year – and stimulated over 500 theoretical papers. However, it was announced in August that new data shows that the significance has dropped to less than 1 sigma. It was just a statistical fluctuation, and there is no such particle.'

There is other data available that appears to support the idea of an accelerating universe, such as information on the cosmic microwave background – the faint afterglow of the Big Bang – from the Planck satellite. However, Professor Sarkar said: 'All of these tests are indirect, carried out in the framework of an assumed model, and the cosmic microwave background is not directly affected by dark energy. Actually, there is indeed a subtle effect, the late-integrated Sachs-Wolfe effect, but this has not been convincingly detected.

'So it is quite possible that we are being misled and that the apparent manifestation of dark energy is a consequence of analysing the data in an oversimplified theoretical model – one that was in fact constructed in the 1930s, long before there was any real data. A more sophisticated theoretical framework accounting for the observation that the universe is not exactly homogeneous and that its matter content may not behave as an ideal gas – two key assumptions of standard cosmology – may well be able to account for all observations without requiring dark energy. Indeed, vacuum energy is something of which we have absolutely no understanding in fundamental theory.'

Professor Sarkar added: 'Naturally, a lot of work will be necessary to convince the physics community of this, but our work serves to demonstrate that a key pillar of the standard cosmological model is rather shaky. Hopefully this will motivate better analyses of cosmological data, as well as inspiring theorists to investigate more nuanced cosmological models. Significant progress will be made when the European Extremely Large Telescope makes observations with an ultrasensitive "laser comb" to directly measure over a ten to 15-year period whether the expansion rate is indeed accelerating.'

Tracking waves from sunspots gives new solar insight

161020104613_1_900x600While it often seems unvarying from our viewpoint on Earth, the sun is constantly changing. Material courses through not only the star itself, but throughout its expansive atmosphere. Understanding the dance of this charged gas is a key part of better understanding our sun -- how it heats up its atmosphere, how it creates a steady flow of solar wind streaming outward in all directions, and how magnetic fields twist and turn to create regions that can explode in giant eruptions. Now, for the first time, researchers have tracked a particular kind of solar wave as it swept upward from the sun's surface through its atmosphere, adding to our understanding of how solar material travels throughout the sun.

Tracking solar waves like this provides a novel tool for scientists to study the atmosphere of the sun. The imagery of the journey also confirms existing ideas, helping to nail down the existence of a mechanism that moves energy -- and therefore heat -- into the sun's mysteriously-hot upper atmosphere, called the corona. A study on these results was published Oct. 11, 2016, in The Astrophysical Journal Letters.

"We see certain kinds of solar seismic waves channeling upwards into the lower atmosphere, called the chromosphere, and from there, into the corona," said Junwei Zhao, a solar scientist at Stanford University in Stanford, California, and lead author on the study. "This research gives us a new viewpoint to look at waves that can contribute to the energy of the atmosphere."

The study makes use of the wealth of data captured by NASA's Solar Dynamics Observatory, NASA's Interface Region Imaging Spectrograph, and the Big Bear Solar Observatory in Big Bear Lake, California. Together, these observatories watch the sun in 16 wavelengths of light that show the sun's surface and lower atmosphere. SDO alone captures 11 of these.

"SDO takes images of the sun in many different wavelengths at a high time resolution," said Dean Pesnell, SDO project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "That lets you see the frequencies of these waves -- if you didn't have such rapid-fire images, you'd lose track of the waves from one image to the next."

Though scientists have long suspected that the waves they spot in the sun's surface, called the photosphere, are linked to those seen in the lowest reaches of the sun's atmosphere, called the chromosphere, this new analysis is the first time that scientists have managed to actually watch the wave travel up through the various layers into the sun's atmosphere.

When material is heated to high temperatures, it releases energy in the form of light. The type, or wavelength, of that light is determined by what the material is, as well as its temperature. That means different wavelengths from the sun can be mapped to different temperatures of solar material. Since we know how the sun's temperature changes throughout the layers of its atmosphere, we can then order these wavelengths according to their height above the surface -- and essentially watch solar waves as they travel upwards.

The implications of this study are twofold -- first, this technique for watching the waves itself gives scientists a new tool to understand the sun's lower atmosphere.

"Watching the waves move upwards tells us a lot about the properties of the atmosphere above sunspots -- like temperature, pressure, and density," said Ruizhu Chen, a graduate student scientist at Stanford who is an author on the study. "More importantly, we can figure out the magnetic field strength and direction."

The effect of the magnetic field on these waves is pronounced. Instead of traveling straight upwards through the sun, the waves veer off, taking a curved path through the atmosphere.

"The magnetic field is acting like railroad tracks, guiding the waves as they move up through the atmosphere," said Pesnell, who was not involved in this study.

The second implication of this new research is for a long-standing question in solar physics -- the coronal heating problem.

The sun produces energy by fusing hydrogen at its core, so the simplest models suggest that each layer of the sun should be cooler as you move outward. However, the sun's atmosphere, called the corona, is about a hundred times hotter than the region below -- counter to what you would expect.

No one has as-yet been able to definitively pinpoint the source of all the extra heat in the corona, but these waves may play a small role.

"When a wave travels upwards, a number of different things can happen," said Zhao. "Some may reflect back downwards, or contribute to heating -- but by how much, we don't yet know."

NASA Goddard built, operates and manages the SDO spacecraft for NASA's Science Mission Directorate in Washington. Lockheed Martin designed the IRIS observatory and manages the mission for NASA. The Big Bear Solar Observatory is operated by the New Jersey Institute of Technology in Newark, New Jersey.

22 Oct 2016

Astronomers find oldest known planetary disk

Astronomers-find-oldest-known-planetary-disk

A group of citizen scientists and professional astronomers, including Carnegie’s Jonathan Gagné, joined forces to discover an unusual hunting ground for exoplanets. They found a star surrounded by the oldest known circumstellar disk—a primordial ring of gas and dust that orbits around a young star and from which planets can form as the material collides and aggregates.

Led by Steven Silverberg of University of Oklahoma, the team described a newly identified red dwarf star with a warm circumstellar disk, of the kind associated with young planetary systems.  Circumstellar disks around red dwarfs like this one are rare to begin with, but this star, called AWI0005x3s, appears to have sustained its disk for an exceptionally long time. The findings are published by The Astrophysical Journal Letters.

"Most disks of this kind fade away in less than 30 million years," said Silverberg. "This particular red dwarf is a candidate member of the Carina stellar association, which would make it around 45 million years old [like the rest of the stars in that group]. It's the oldest red dwarf system with a disk we've seen in one of these associations."

The discovery relied on citizen scientists from Disk Detective, a project led by NASA/GSFC's Dr. Marc Kuchner that’s designed to find new circumstellar disks. At the project’s website, Disk Detective.org, users make classifications by viewing ten-second videos of data from NASA surveys, including the Wide-field Infrared Survey Explorer mission (WISE) and Two-Micron All Sky Survey (2MASS) projects. Since the launch of the website in January 2014, roughly 30,000 citizen scientists have participated in this process, performing roughly 2 million classifications of celestial objects.

"Without the help of the citizen scientists examining these objects and finding the good ones, we might never have spotted this object," Kuchner said. "The WISE mission alone found 747 million [warm infrared] objects, of which we expect a few thousand to be circumstellar disks.”

“Unravelling the mysteries of our universe, while contributing to the advancement of astronomy, is without a doubt a dream come true,” says Hugo Durantini Luca from Argentina, one of eight citizen scientist co-authors. 

Determining the age of a star can be tricky or impossible. But the Carina association, where this red dwarf was found, is a group of stars whose motions through the Galaxy indicate that they were all born at roughly the same time in the same stellar nursery.

Carnegie’s Gagné devised a test that showed this newly found red dwarf and its disk are likely part of the Carina association, which was key to revealing its surprising age.

“It is surprising to see a circumstellar disk around a star that may be 45 million years old, because we normally expect these disks to dissipate within a few million years,” Gagné explained. “More observations will be needed to determine whether the star is really as old as we suspect, and if it turns out to be, it will certainly become a benchmark system to understand the lifetime of disks."

Knowing that this star and its disk are so old may help scientists understand why M dwarf disks appear to be so rare.

This star and its disk are interesting for another reason: the possibility that it could host extrasolar planets. Most of the extrasolar planets that have been found by telescopes have been located in disks similar to the one around this unusual red dwarf. Moreover, this particular star is the same spectral type as Proxima Centauri, the Sun's nearest neighbour, which was shown to host at least one exoplanet, the famous Proxima b, in research published earlier this year.

21 Oct 2016

Thirty Meter Telescope: Fresh Hearings To take place

top-view-tmt-complexFresh hearings to decide the fate of the planned Thirty Meter Telescope (TMT) began Thursday in Hilo, Hawaii. The proceedings, which will decide whether the stalled construction work at the Big Island's Mauna Kea mountain will go ahead, are expected to last until next month.

The hearings come almost a year after the Supreme Court of Hawaii revoked a permit that would have allowed the construction of TMT to proceed atop the Mauna Kea summit. In a December ruling, the court said that the land board’s approval process was flawed.

On Thursday, environmental planner Perry White, principal author of the permit application filed by the University of Hawaii for the TMT project, argued that the project met the criteria for land use in a state-designated conservation district.

“White ... also noted that the Thirty Meter Telescope will be situated within the Maunakea area already sub-zoned for astronomy-related purposes,” the TMT project collaboration said in a statement. “He stressed that the project will not cause substantial adverse impacts to existing natural resources within the surrounding area, community or region.”

If constructed, the $1.4 billion telescope would be one of the world’s largest. Designed to operate in near-ultraviolet and mid-infrared wavelengths, the TMT would have a much higher resolution than that of the Hubble Space Telescope, allowing scientists to glimpse the universe in its infancy. Mauna Kea, which is a dormant volcano, is the ideal site as it provides a clear view of the sky for most part of the year, with little air and light pollution.

However, the site is considered sacred by some native Hawaiians, who say that the land contains burials, monuments, and places of worship venerated by them. Some environmentalists have also opposed the telescope’s construction, claiming that it would damage the ecosystem and harm the existing physical and environmental aspects of the land.

“This is a very simple case about land use,” Kealoha Pisciotta, a former telescope operator on Mauna Kea who has, over the past decade, led protests against the TMT, told the New York Times earlier this month. “It’s not science versus religion. We’re not the church. You’re not Galileo.”

20 Oct 2016

Milky Way: Secrets of galaxy revealed in most detailed hydrogen map yet

A team of scientists from Australia and Germany have created the most detailed hydrogen map ever produced of the Milky Way.

The map was pieced together using data collected over the past 10 years by two radio telescopes.

Perth-based astronomer Professor Lister Staveley-Smith, from the International Centre for Radio Astronomy Research (ICRAR), said other studies had mapped smaller areas of the galaxy in greater detail, but this map was the first of its quality covering the whole sky.

"We've kind of just put the data together from both hemispheres, a bit like putting maps of our own world together from the Northern Hemisphere and the Southern Hemisphere and picturing the globe for the first time," Professor Staveley-Smith told the ABC.

Astronomers used the two telescopes — in Parkes, New South Wales and Effelsberg, Germany — to study neutral hydrogen, the most abundant element in the universe.

"What it gives us is a map of the sky in hydrogen that normal telescopes, normal optical telescopes, can't see," Professor Staveley-Smith said.

The map, produced by a survey named the HI4PI, shows the Milky Way's finer details, including the boundaries of super shells created by giant explosions.
"We're seeing gas, we're seeing the interstellar medium, we're seeing the stuff which stars will later form from," he said.

"It's very important to understand the structure of gas in our own galaxy and the amount of gas in our own galaxy, its dynamics, in order that we can study the past evolution of the Milky Way and its likely future evolution."

An animation of the data shows two revolving spheres, similar to the globe of the Earth, with the sky plotted on each.

"Instead of viewing that sphere from the inside, which is what we do when we look at the sky, we can sort of paint that picture on the outside of a globe and sort of take ourselves outside and look at the sky the other way around," Professor Staveley-Smith said.

The map's sensitivity means scientists can see the two nearest galaxies to Earth — the Magellanic Clouds — and the stream of gas flowing from them across the Milky Way.

"I think this map, for the first time, will allow us to piece together the exact continuity of that stream across the two hemispheres," he said.

"That's what I'm most excited about."

Professor Staveley-Smith, who is based at the University of Western Australia, said only the Square Kilometre Array (SKA) telescope would produce maps of higher resolution.

The SKA, which will be the world's largest radio telescope, is being built in WA and South Africa.

Scientists from the HI4PI project have published their findings in the journal Astronomy and Astrophysics.

18 Oct 2016

Inter-stellar travel Poses Unique Threat to Astronauts

image_4267e-Deep-Space-Travel

Exposure to highly energetic charged particles can lead to a range of potential central nervous system complications that can occur during and persist long after space travel, says a team of researchers led by Prof. Charles Limoli of the University of California, Irvine.

“The current findings raise much greater alarm. This is not positive news for astronauts deployed on a two-to-three-year round trip to Mars,” said Prof. Limoli, who is the senior author of a rodent study published in Monday’s issue of the journal Scientific Reports.

“The space environment poses unique hazards to astronauts. Exposure to these particles can lead to a range of potential central nervous system complications that can occur during and persist long after actual space travel – such as various performance decrements, memory deficits, anxiety, depression and impaired decision-making.”

“Many of these adverse consequences to cognition may continue and progress throughout life,” he said.

For the study, rodents were subjected to charged particle irradiation — fully ionized oxygen and titanium — at the NASA Space Radiation Laboratory.

Six months after exposure, Prof. Limoli and his colleagues still found significant levels of brain inflammation and damage to neurons.

High resolution imaging revealed that the brain’s neural network was impaired through the reduction of dendrites and spines on these neurons, which disrupts the transmission of signals among brain cells. These deficiencies were parallel to poor performance on behavioural tasks designed to test learning and memory.

In addition, the researchers discovered that the radiation affected ‘fear extinction,’ an active process in which the brain suppresses prior unpleasant and stressful associations, as when someone who nearly drowned learns to enjoy water again.

“Deficits in fear extinction could make you prone to anxiety, which could become problematic over the course of a three-year trip to and from Mars,” Prof. Limoli said.

Most notably, these results mirror the six-week post-irradiation findings of Prof. Limoli’s 2015 study.

Similar types of more severe cognitive dysfunction are common in brain cancer patients who have received high-dose, photon-based radiation treatments.

“While dementia-like deficits in astronauts would take months to manifest, the time required for a mission to Mars is sufficient for such impairments to develop,” Prof. Limoli said.

“People working for extended periods on the International Space Station, however, do not face the same level of bombardment with galactic cosmic rays because they are still within the Earth’s protective magnetosphere.”

This work is part of NASA’s Human Research Program. Investigating how space radiation affects astronauts and learning ways to mitigate those effects are critical to further human exploration of space, and NASA needs to consider these risks as it plans for missions to Mars and beyond.

“Partial solutions are being explored. Spacecraft could be designed to include areas of increased shielding, such as those used for rest and sleep,” Prof. Limoli said.

“However, these highly energetic charged particles will traverse the ship nonetheless, and there is really no escaping them.”

17 Oct 2016

Air Force gets space telescope that can see the detail of satellites in orbit

podcast-update-graphic-v2-100687981-large_idge

The DARPA-developed Space Surveillance Telescope (SST) will this week get a new permanent home in Australia with the Air Force Space Command where it promises to rapidly bolster the nation’s ability to more quickly spot and track faint objects in space.

160927-D-ZZ999-002AThe Air Force, says the SST features unique image-capturing technology known as a curved charge coupled device (CCD) system,  as well as very wide field-of-view, large-aperture optics, and doesn't require the long optics train of a more traditional telescopes. The design makes the SST less cumbersome on its moveable mount, letting it survey the sky rapidly, the Air Force says. The telescope's mount uses advanced servo-control technology, making the SST one of the most agile telescopes of its size ever built.

With 2.2 million asteroid observations in 2014, 7.2 million in 2015 and hopes for 10 million in 2016, SST has already become the most prolific tool for asteroid observation in the world. SST also has discovered 3,600 new asteroids and 69 near-Earth objects, including four that carry a risk of hitting Earth, DARPA says.

From DARPA: "Beyond providing faster data collection, the SST is very sensitive to light, which allows it to see faint objects in deep space that currently are impossible to observe. The detection and tracking of faint objects requires a large aperture and fast optics.  The SST uses a 3.5 meter primary mirror, which is large enough to achieve the desired sensitivity. The system is an f/1.0 optical design, with a large-area mosaic CCD camera constructed from the curved imagers and a high-speed shutter allowing for fast scanning at the high sensitivity."

The SST has a number of missions, watching for debris in low earth orbit to help existing satellites avoid collisions chief among them, it also tracks objects in deep space and offers astronomers a wide-angle lens to take astronomical surveys of stars and comets, DARPA says.

A view of the M20 Trifid Nebula, taken by the Defense Advanced Research Projects Agency’s advanced Space Surveillance Telescope, soon to be transitioned to the Air Force and moved to Australia, where it will provide key space situational awareness from the southern hemisphere -- a still largely unexplored area of the geosynchronous belt. DoD photo Credit: Dod/DARPA

“Space is congested with tens of thousands of manmade objects as well as micro-meteors, asteroids and other natural satellites,” Lindsay Millard wrote in a post on the DARPA website. “[And] space is contested by a range of manmade threats that may have adverse effects on satellites.”

SST’s wide-open eye on the sky promises to become the most prolific tool ever for observing near-Earth objects and potentially harmful asteroids. The Air Force and Australian Government have announced plans to move SST to Australia and operate it jointly. From its new home, SST will provide key space situational awareness information from the southern hemisphere—an area of the geosynchronous belt that is currently sparsely observed, DARPA said.

Ripples in space key to understanding cosmic rays

mms_background_smallerIn a new study researchers at the Swedish Institute of Space Physics have used measurements from NASA's MMS (Magnetospheric MultiScale) satellites to reveal that there are ripples, or surface waves, moving along the surface of shocks in space. Such ripples in shocks can affect how plasma is heated and are potential sites of particle acceleration. These results have been published in the latest issue of Physical Review Letters.

Most visible matter in the Universe consists of ionized gas known as plasma. Shock waves in plasmas form around planets, stars and supernovas. Shocks in space plasma are efficient particle accelerators. Shocks in supernova explosions are thought to be the main source of cosmic rays – very high energy charged particles from space.

 

The details on how particles are accelerated and how plasma is heated at shocks in space plasmas are still unclear. The shock waves are usually considered planar surfaces but numerical simulations have previously showed that ripples can form on the surface of shock waves. The elusive ripples have been hard to study in space due to their small size and high speed.

A new study, by researchers at the Swedish Institute of Space Physics (IRF) in Uppsala, shows that these ripples do in fact exist in the Earth's bow shock. The study uses the newly launched MMS mission to study the shock in unprecedented detail.

"With the new MMS spacecraft we can, for the first time, resolve the structure of the bow shock at these small scales," says Andreas Johlander, PhD student at IRF, who led the study.

The results are of importance to the broader field of astrophysics where these ripples are thought to play an important role in accelerating particles to very high energies. The structure of the shock wave also determine how plasma is deflected and heated at shocks.

"These direct observations of shock ripples in a space plasma allow us to characterize the physical properties of the ripples. This brings us one step closer to understanding how shocks can produce cosmic rays," says Andreas Johlander.

Antimatter and the Sail to propel spacecraft to our nearest star

h_pbarsail_concept_02

by Paul Gilster on October 17, 2016

An antimatter probe to a nearby star? The idea holds enormous appeal, given the colossal energies obtained when normal matter annihilates in contact with its antimatter equivalent. But as we’ve seen through the years on Centauri Dreams, such energies are all but impossible to engineer. Antimatter production is infinitesimal, the by-product of accelerators designed with a much different agenda. Moreover, antimatter storage is hellishly difficult, so that maintaining large quantities in a stable condition requires multiple breakthroughs.

All of which is why I became interested in the work Gerald Jackson and Steve Howe were doing at Hbar Technologies. Howe, in fact, became a key source when I put together the original book from which this site grew. This was back in 2002-2003, and I was captivated with the idea of what could be called an ‘antimatter sail.’ The idea, now part of a new Kickstarter campaign being launched by Jackson and Howe, is to work with mere milligrams of antimatter, allowing antiprotons to be released from the spacecraft into a uranium-enriched, five-meter sail.

Reacting with the uranium, the antimatter produces fission fragments that create what could be considered a nuclear-stimulated ablation blowing off the carbon-fiber sail. As to the reaction itself, Jackson and Howe would use a sheet of depleted uranium U-238 with a carbon coating on its back side. Here’s how the result is described in the Kickstarter material now online:

When antiprotons… drift onto the front surface, their negative electrical charge allows them to act like an orbiting electron, but with different quantum numbers that allow the antiprotons to cascade down into the ground orbital state. At this point it annihilates with a proton or neutron in the nucleus. This annihilation event causes the depleted uranium nucleus to fission with a probability approaching 100%, most of the time yielding two back-to-back fission daughters.

Now we get into a serious kick for the spacecraft:

A fission daughter travelling away from the sail at a kinetic energy of 1 MeV/amu has a speed of approximately 13,800 km/sec, or 4.6% of the speed of light. The other fission daughter is absorbed by the sail, depositing its momentum into the sail and causing the sail (and the rest of the ship) to accelerate.

The concept relies, as Jackson said in a recent email, on using antimatter as a spark plug rather than as a fuel, converting the energy from proton-antiproton annihilations into propulsion.

original

Image: The original antimatter probe concept. Credit: Gerald Jackson/Hbar Technologies.

The current work grows out of a 2002 grant from NASA’s Institute for Advanced Concepts but the plan is to develop the idea far beyond the Kuiper Belt mission Jackson and Howe initially envisioned. Going interstellar would take not milligrams but tens of grams of antimatter, far beyond today’s infinitesimal production levels. In fact, while the Fermi National Accelerator laboratory has been able to produce no more than 2 nanograms of antimatter per year, even that is high compared to CERN’s output (the only current source), which is 100 times smaller.

Even so, interest in antimatter remains high because of its specific energy — two orders of magnitude larger than fusion and ten orders of magnitude larger than chemical reactions — making further research highly desirable. If the fission reaction the antimatter produces within the sail is viable, we will be able to demonstrate a way to harness those energies, with implications for deep space exploration and the possibility of interstellar journeys.

The original NIAC work led to a sail 5-meters in diameter, with a 15-micron thick carbon layer and a uranium coating 293 microns thick. Interestingly, the study showed that the sail had sufficient area to remove any need for active cooling of the surface. Indeed, the steady-state temperature of the sail would be 570 Celsius, below the melting point of uranium.

The work was based around a 10 kg instrument payload to be delivered to 250 AU within 10 years. Turning to interstellar possibilities, Breakthrough Star shot has been talking about reaching 20 percent of light speed with a beamed laser array pushing small sails. Jackson and Howe now seek roughly 5 percent of c, making for a mission of less than a century to reach Proxima Centauri, where we already know an interesting planet awaits.

But here’s a significant difference: Unlike Breakthrough Star shot's flyby assumptions, the antimatter sail mission concept is built around decelerating and attaining orbit around the target star. In the absence of magsail braking against Proxima’s stellar wind, this would presumably also involve antimatter, braking with the same methods to allow for long-term scientific investigation, thus avoiding the observational challenges of a probe pushing past a small and probably tidally-locked planet at 20 percent of light speed.

Here’s how Jackson describes deceleration in his recent email:

Our project considers deceleration and orbit about the destination star a mission requirement. There are serious implications for spacecraft velocity when the requirement of deceleration at the destination is imposed. Either drag or some other mechanism needs to be invoked at the destination, or enough extra fuel must be accelerated in order to accomplish a comparable deceleration. Because the rocket equation equates probe velocity with mass utilization, a staged spacecraft architecture is envisioned wherein a more massive booster accelerates the spacecraft and a smaller second stage decelerates into the destination solar system.

The discovery of Proxima b, that interesting planet evidently in the habitable zone around the nearest star, continues to energize the interstellar community. The Kickstarter campaign, just underway and with a goal of $200,000, hopes to upgrade earlier antimatter sail ideas into the interstellar realm. Tomorrow I want to say a few more things about the antimatter sail and the issues the Kickstarter campaign will address as it expands the original work.